Mid Canterbury's diverse farming community could have one irrigation scheme in the future to secure water for farmers, says Barrhill Chertsey Irrigation general manager, John Wright.

He was speaking to University of the Third Age (U3A) members at their last meeting, giving them a brief history of Mid Canterbury irrigation. U3A is social group that gives education and stimulation to its mainly retired community members - those in their ''third age''.

Mr Wright has a Mid Canterbury farming background and knows the importance of water to the district.

''Irrigation drives the Ashburton [farming] district, with 90% of the plains irrigated nowadays.''

And there was plenty of water if it was used efficiently. he said, which was the key to continual supply in Mid Canterbury.

Dams in South Canterbury gave farmers in that region the reliability of supply, but Mid Canterbury's water supplies came from the alpine-fed Rangitata and Rakaia rivers and needed to be managed efficiently.

He said the district had a range of soil for intensive arable but also livestock, particularly dairy cows.

''There is a lot of diversity as a result, making it a resilient community,'' he said.

Mr Wright spoke of the early planning of the Rangitata Diversion Race, its construction in the 1930s, the groundwater drilling in the 1970s and Barrhill Chertsey Irrigation and Acton schemes.

He said getting permission for irrigation schemes then was a long, drawn-out process, but were much quicker now, with uptake needed within one to three years.

Mid Canterbury had experienced massive increases of irrigation use in the early 2000s.

He remembered as a child in Hinds helping change from the wild-flooding system to border dykes, which were slightly more controlled, he said.

Centre pivots had changed water efficiency across the county - the new centre-pivot irrigators used only about one-fifth of the water used by border-dyking.

There was also a transfer of value, with water run-off used at Trustpower's Highbank power station.

In the 1960s schemes we run by irrigation societies, but in the 2000s they were co-operative companies.

By 2011, some irrigation schemes formed Irrigo to co-ordinate administration services and reduce costs. Acton Farmers Irrigation Co-op, Ashburton Lyndhurst Irrigation and BCI were a part of this group. Then in 2017, the Mayfield, Hinds and Valetta schemes merged.

Mr Wright said it was possible there would be just one big one irrigation scheme in Mid Canterbury in future.